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5. Effects of short-term GH supplementation and treadmill exercise training on physical performance and skeletal muscle apoptosis in old rats

Author

Marzetti, Emanuele, Groban, Leanne, Wohlgemuth, Stephanie E., Lees, Hazel A., Lin, Marina, Jobe, Harrison, Giovannini, Silvia, Leeuwenburgh, Christiaan, and Carter, Christy S.

Subjects
Muscle cells -- Research, Cellular control mechanisms -- Research, Hormone therapy -- Research, Muscles -- Research, Exercise -- Physiological aspects, Exercise -- Research, Cell research, Hormone research, Biological sciences
Abstract

Growth hormone (GH) supplementation at old age has been shown to improve body composition, although its effect on muscle performance is still debated. On the other hand, resistance training increases muscle mass and strength even when initiated at advanced age. In the present study, we investigated the effects of short-term GH supplementation and exercise training on physical performance and skeletal muscle apoptosis in aged rats. Old (28 mo) male Fischer 344 x Brown Norway rats were randomized to 4 wk of GH supplementation (300 [micro]g subcutaneous, twice daily) or 4 wk of treadmill running or used as sedentary controls. Eight-month-old rats, sedentary or exercised, were used as young controls. Exercise training improved exercise capacity and muscle strength in old animals. In soleus muscle, age and exercise were not associated with significant changes in the extent of apoptosis. However, we detected an age-related increase of cleaved caspase-8 (+98%), cleaved caspase-3 (+ 136%), and apoptotic DNA fragmentation (+203%) in the extensor digitorum longus muscle of old sedentary rats, which was attenuated by exercise. GH administration neither ameliorated physical performance nor attenuated apoptosis in extensor digitorum longus and was associated with increased apoptosis in soleus muscle (+206% vs. old controls). Our findings indicate that a short-term program of exercise training started at advanced age reverses age-related skeletal muscle apoptosis and represents an effective strategy to improve physical performance. In contrast, shortterm administration of GH late in life does not provide any protection against functional decline or muscle aging and may even accelerate apoptosis in slow-twitch muscles, such as the soleus. aging; sarcopenia; growth hormone; muscle quality; tumor necrosis factor-[alpha]

Published
2008

10. Myogenic and proteolytic mRNA expression following blood flow restricted exercise

Author

Manini TM, Todd M., Vincent, Kevin R., Leeuwenburgh, Christiaan L., Lees, Hazel A., Kavazis, Andreas N., Borst, Stephen E., and Clark, Brian C.

Subjects
Adult, Male, Electromyography, Muscle Proteins, Resistance Training, Hypertrophy, Muscle Development, Article, Quadriceps Muscle, Young Adult, Regional Blood Flow, Humans, Female, RNA, Messenger
Abstract

Resistance exercise performed at low loads (20-30% of maximal strength) with blood flow restriction (BFR) acutely increases protein synthesis and induces hypertrophy when performed chronically. We investigated myogenic and proteolytic mRNA expression 8 h following an acute bout of knee extension exercise.Fifteen subjects (22.8 ± 3.7 years, eight men and seven women) were randomized to two exercise conditions: BFR or control exercise. All participants performed four sets of exercise (30, 15, 15 and 15 repetitions) at 20% of maximal strength. Persons in the BFR group had a cuff placed on the upper thigh inflated to 1.5 times brachial systolic blood pressure (cuff pressure range: 135-186 mmHg). Muscle biopsies from the vastus lateralis were excised 24 h before and 8 h following the exercise. RT-PCR analysis demonstrated no change in myogenic gene expression (insulin-like growth factor-1, MyoD, myogenin, myostatin - a negative regulator) with either exercise condition (P0.123). However, BFR exercise downregulated mRNA expression in transcripts associated with proteolytic pathways (FOXO3A, Atrogin-1 and MuRF-1) with no change in the control exercise condition. Specifically, median mRNA expression of FOXO3A decreased by 1.92-fold (P = 0.01), Atrogin-1 by 2.10-fold (P = 0.01) and MuRF-1 by 2.44-fold (P = 0.01). These data are consistent with the downregulation of proteolytic transcripts observed following high-load resistance exercise. In summary, myogenic genes are unchanged and proteolytic genes associated with muscle remodelling are reduced 8 h following low-load BFR exercise.

Published
2011

12. Late-life enalapril administration induces nitric oxide-dependent and independent metabolic adaptations in the rat skeletal muscle

Author

Marzetti, Emanuele, primary, Calvani, Riccardo, additional, DuPree, Jameson, additional, Lees, Hazel A., additional, Giovannini, Silvia, additional, Seo, Dong-oh, additional, Buford, Thomas W., additional, Sweet, Kindal, additional, Morgan, Drake, additional, Strehler, Kevin Y. E., additional, Diz, Debra, additional, Borst, Stephen E., additional, Moningka, Natasha, additional, Krotova, Karina, additional, and Carter, Christy S., additional

Published
2012
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13. Skeletal Muscle Apoptotic Signaling Predicts Thigh Muscle Volume and Gait Speed in Community-Dwelling Older Persons: An Exploratory Study

Author

Marzetti, Emanuele, primary, Lees, Hazel A., additional, Manini, Todd M., additional, Buford, Thomas W., additional, Aranda, Juan M., additional, Calvani, Riccardo, additional, Capuani, Giorgio, additional, Marsiske, Michael, additional, Lott, Donovan J., additional, Vandenborne, Krista, additional, Bernabei, Roberto, additional, Pahor, Marco, additional, Leeuwenburgh, Christiaan, additional, and Wohlgemuth, Stephanie E., additional

Published
2012
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14. An Exploratory Analysis of the Effects of a Weight Loss Plus Exercise Program on Cellular Quality Control Mechanisms in Older Overweight Women

Author

Wohlgemuth, Stephanie E., primary, Lees, Hazel A., additional, Marzetti, Emanuele, additional, Manini, Todd M., additional, Aranda, Juan M., additional, Daniels, Michael J., additional, Pahor, Marco, additional, Perri, Michael G., additional, Leeuwenburgh, Christian, additional, and Anton, Stephen D., additional

Published
2011
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15. Mitochondrial regulation is altered in skeletal muscle from high and low functioning elderly individuals

Author

Joseph, Anna‐Maria, primary, Wohlgemuth, Stephanie E., additional, Adhihetty, Peter J., additional, Buford, Thomas W., additional, Lees, Hazel A., additional, Aranda, Juan M., additional, Sandesara, Bhanuprasad D., additional, Pahor, Marco, additional, Manini, Todd M., additional, Marzetti, Emanuele, additional, and Leeuwenburgh, Christiaan, additional

Published
2011
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17. Differential effects of enalapril and losartan on body composition and indices of muscle quality in aged male Fischer 344 × Brown Norway rats

Author

Carter, Christy S., primary, Giovaninni, Silvia, additional, Seo, Dong-Oh, additional, DuPree, Jameson, additional, Morgan, Drake, additional, Chung, Hae Young, additional, Lees, Hazel, additional, Daniels, Michael, additional, Hubbard, Gene B., additional, Lee, Shuko, additional, Ikeno, Yuji, additional, Foster, Thomas C., additional, Buford, Thomas W., additional, and Marzetti, Emanuele, additional

Published
2010
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24. Photosynthetic redox imbalance influences flavonoid biosynthesis in Lemna gibba.

Author

AKHTAR, TARIQ A., LEES, HAZEL A., LAMPI, MARK A., ENSTONE, DARYL, BRAIN, RICHARD A., and GREENBERG, BRUCE M.

Subjects
*FLAVONOIDS, *NITROGEN excretion, *FREE electron theory of metals, *PHOTOSYNTHETIC oxygen evolution, *REACTIVE oxygen species
Abstract

Plants accumulate flavonoids in response to a myriad of environmental challenges, especially when exposed to ultraviolet (UV) radiation or situations causing oxidative stress. However, the origin and nature of the signal triggering their accumulation remain obscure. In this study, a group of flavonoids belonging to the flavone class was identified in Lemna gibba (duckweed). These flavones accumulated upon exposure to UV radiation, low temperature, copper and the photosynthetic electron transport (PET) inhibitors 2,5-dibromo-3-methyl-6-isopropyl- p-benzoquinone (DBMIB) and 1,2-dihydroxyanthraquinone (DHATQ). All of these stressors were also shown to promote PET chain (PETC) reduction; however, in the co-presence of 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU) or a light regime that oxidized the PETC, flavonoid accumulation ceased. Chloroplast-derived reactive oxygen species (ROS) were not associated with all of the stress conditions that promoted both PETC reduction and flavonoid synthesis, indicating that ROS were not a strict requisite for flavonoid accumulation. Transcripts for the flavonoid biosynthetic genes, chalcone synthase (CHS) and chalcone isomerase, were similarly responsive to the PETC redox state, as were a panel of transcripts revealed by differential display PCR. Collectively, these results provide evidence that PETC redox status is one of the factors affecting flavonoid biosynthesis. [ABSTRACT FROM AUTHOR]

Published
2010
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